Prenatal Visit Guidelines

Clinic A/P, adults, OB/GYN

 –
The attending physician must see all prenatal patients.
 Pregnancy Confirmation 
  • Urine Pregnancy
  • Dating U/S
  • Prenatal folder – Prenatal Vitamins
  • TSH (if history of hypothyroidism, TSH <2.5)
  • Be cognizant of time-sensitive labs – Depending on EDD
Initial Visit
  • Complete H&P
  • Type & Rh
  • Antibody Screen
  • CBC (H/H, Plt, MCV)
  • Thalassemia – all Asians
  • Rubella Titer
  • Varicella Titer
  • RPR
  • Hep BsAg
  • Hep C Ab – if high-risk
  • GC / Chlamydia
  • UA and Urine Culture
  • Quantiferon or PPD / CXR (PRN)
  • Pap smear / HPV (If not UTD)
  • HIV
  • CF screen ⇒ “Genetic consult” if carrier of “+”
  • Hgb A1C (is not really good during pregnancy? check)
  • TSH
  • Fasting blood glucose
  • Get a dating U/S if irregular menses or unsure LMP, if not yet done.
  • Create checklist in problem list
 12 Weeks
  •  Fetal heart rate (FHT) -now & at every visit
    (    Fetal heart sound is first heard at 11-12 weeks by pocket Doppler)
 10.0 to 13.6 Weeks
  •  First Trimester Screening (hCG and plasma protein-A (PAPP-A)
    **Different timing than U/S.
 11.2 to 14.2 Weeks
  •  Nuchal translucency (NT) Ultrasound.
    *Different timing than blood work*
    *Order (fetal care and genetics ⇒ 1st tri screen / NT / Genetic counsel)
 9 to 20 Weeks
  •  CVS / Amniocentesis
 15.0 to 20 Weeks (prefer 16-18)
  •  Second Trimester Screen (This is the Quad Screen: AFP, hCG, uE3, and inhibin-A)
 18-20 Weeks
  •  Anatomy Scan. *Order (“fetal care genetics ⇒ U/S > 14 wks”)
    This is a routine U/S done for fetal anatomy survey. For high-risk pregnancy or unsure LMP, get an early U/S det. the GA
 20 Weeks
  •  Fundal Height at every visit
 24-28 Weeks
  •  2hr GTT
  •  Recheck CBC
 27-36 Weeks
  •  Tdap, Rhogam (if Rh negative), Fetal kick counts (10 kicks in 1 hour), L&D precautions. *Order Breast Pump (DME)
 36 Weeks
  • GBS (repeat q4 weeks until delivery if “negative”

The USPSTF strongly recommends screening for hepatitis B virus infection in pregnant women at their first prenatal visit.

Sources:
– NIH.Gov, What tests might I need during pregnancy?
– NIH.Gov, What happens during prenatal visits?

First and Second Trimester Screening

Prenatal Visit Schedule

Healthy pregnancies will go by the following schedule.

0 – 28 weeks: Monthly  (every four weeks)
 28 – 36 weeks: Every 2 weeks
 36 weeks to birth: Weekly

 

What will happen at each visit?
At every visit, we will:

  • Check BP.
  • Check weight and assess weight gain.
  • Urinalysis (UA) – urine culture is done at the first visit, after that, a UA is done at every subsequent visit.
  • Fundal Height
  • FHT (Fetal heart tones) – Starting at 11-12 weeks.
  • Edema – Check hands and feet for swelling.
  • Education – Answer questions or address concerns. Have patients write questions down and bring.
  • Pelvic/cervix exam: 1st visit and any other visits if the patient is having contractions, bleeding, discharge, leaking, or at term.

Palpate to determine the fetal position after 36 weeks but not before due to inaccuracies and discomfort.
Follow the above table to do tests, such as blood tests or an ultrasound exam.

*Antenatal testing (NST / AFI) – Bi-weekly
-Start at 36 weeks if:

  • Advanced Maternal Age
  • HTN / Pre-Eclampsia
  • GDM

Naegele’s rule
Used to calculate EDD (Estimated Date of Delivery) or EDC (Estimated Date of Confinement) from the 1st day of the LMP.
EDD = Add 7 to the date of the 1st day of LMP and  count back 3 months. I.e.
EDD =( 7 + 1st day of LMP) – 3 months.
Of course, when you get your answer, the due date will be in the next calendar year. I.e. add 1 year to the answer above.

Pregnancy wheels may have a five-day error. A lot of docs now use electronic devices to calculate EDC
Use U/S dating if LMP unsure, unreliable, or abnormal. Some studies have suggested exclusive use of U/S date if it was done before 22 weeks gestation.

Fetal Development
Fetal heart sound is first heard at 11-12 weeks by pocket Doppler and 16-19 weeks by Delee fetal stethoscope.
Fundal height: Palpable at the pubic symphysis at 12 weeks, midway between symphysis and umbilicus at 16 weeks, umbilicus at 20 weeks.

 

Image from rphcm.allette.com.au

Image from rphcm.allette.com.au

GnP(TPAL) e.g.  G6P3124.
Gn: Total number of pregnancies
T: Total number of term deliveries (≥37 weeks)
P: Total number of preterm deliveries (20-37 weeks)
A: Total number of abortions or miscarriages (<20 weeks)
L: Total number of living children.

 

Resources:
Thomas Zeng, MD, Obstetrics & Gynecology, Comprehensive Handbook, 2nd Edition. Pages
First-Trimester or Second-Trimester Screening, or Both, for Down’s Syndrome

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